No more errors like this in the logs!
```
INFO 2018-01-05T18:33:15.942Z Message.saveErrors: null Error
at file:///C:/Users/Test/AppData/Local/Programs/signal-desktop/resources/app.asar/js/libtextsecure.js:30:33
at file:///C:/Users/Test/AppData/Local/Programs/signal-desktop/resources/app.asar/js/libtextsecure.js:138:3
at file:///C:/Users/Test/AppData/Local/Programs/signal-desktop/resources/app.asar/js/libtextsecure.js:40718:3
```
It has no information in the title, and then the callstack points to
the `new Error()` line in the old `errors.js`.
This change will include the actual error name and message details in
the stack, and will include the original http error stack as well if
provided.
6464d0a5fa